Engine oil will also effect fuel consumption and mileage. The higher the oil viscosity (thickness) the more parasitic drag is created on rotating and moving internal components robbing the engine of horsepower. Changing oil every 3,000 miles will eliminate an oil breakdown and sludge from building up. Also, changing the oil at regular intervals reduces engine wear on internal engine components. As internal components wear, the engine will begin to lose compression and power.
The weather is also a contributor to fuel consumption. During colder winter months, engines will tend to run richer. Engines should be winterized with thinner viscosity oil and make sure proper amount of anti-freeze has been added.
The condition of an air filter element can contribute immensely to the performance and fuel consumption of the engine. The purpose of the air filter, of course, is to capture any elements in the air while entering the intake system. A dirty air cleaner will restrict the airflow entering the intake and throttle body, causing the engine to work harder to draw air into it. To obtain optimum fuel consumption, it's all about a clean air filter element allowing the air/fuel mixture to atomize and burn cleanly.
Fuel Additives are basically fuel-soluble chemicals that can be added to gasoline to enhance certain performance characteristics. Deposit control additives can help eliminate carbon buildup on intake system components and reduce the harmful effects of combustion chamber deposits. The additive chemicals pull carbon deposits away from metal surfaces, such as combustion chambers, intake valves, and fuel injectors, and then burn them away in the combustion process.
The purpose of a catalytic converter is to reduce the harmful emissions from the exhaust of a combustion engine. This is accomplished by a combination of heat and precious metal catalyst that causes harmful emissions to either oxidize or reduce to safe elements in the exhaust flow.
The precious metal catalyst is bound to an extruded ceramic honeycomb substrate. The ceramic honeycomb has hundreds of flow channels, allowing the exhaust gases to come in contact with a surface area, like flypaper, where a chemical reaction takes place.
If the ceramic inside the converter becomes clogged or coated with carbon, lead, or oil, its efficiency is greatly reduced. The vehicle's fuel mileage will be hindered due to the restriction of the ceramic honeycomb and should be replaced.
It is proven that automatic Overdrive transmissions will definitely increase fuel mileage. An Overdrive has a faster output speed than input speed, which is the opposite of a reduction. An automatic transmission with Overdrive will accomplish less engine rpm, which will increase fuel mileage.